You program the Timer for the number of minutes of water flow, and the number of minutes for the waiting time. After it is attached to your shower the settings cannot be changed by any users. (See instructions for reprogramming the settings)

Once the Start button is pressed the full cycle must be completed before another shower can be started. (The water flow does not control the program)

The digital display counts down the minutes along with an audible sound to keep the user well aware of the time remaining for their shower.